Apparatus for forming a member from a slurry of material

ABSTRACT

An improved machine or apparatus for forming member from a slurry of refractory material includes a pair of mold sections which cooperate to form a cavity. A flexible diaphragm extends around the mold sections and is movable to an inwardly and downwardly sloping position to form a trough connected in fluid communication with the mold cavity. The mold cavity is flooded by filling the trough with the slurry of refractory material. Water is then drawn from the slurry in the mold cavity to form a wetcake of refractory material. The water content of this wet-cake of refractory material is at least partially controlled with an adjustable timer which regulates the length of time for which water is drawn from the mold cavity. After sufficient refractory material has been deposited in the mold cavity to form a wet-cake having the shape of the member to be formed, the diaphragm is moved to an outwardly and downwardly sloping position to enable excess slurry to flow away from the mold sections and into a receptacle. While the diaphragm is in this outwardly and downwardly sloping position, a water and air spray or washdown is applied to the area around the upper mold section to remove any refractory material which may settle out of the excess slurry. The excess slurry is pumped from this receptacle to a main mixing or batch tank where it is mixed with a relatively large quantity of the slurry. Therefore, when this excess slurry is subsequently reused, it will have a water content or consistency corresponding to that of the main batch of slurry.

' United States- Patent 3,439,734 4/1969 Eastwood....

[72} Inventor Martin Eversdyk Bedlord Heights. Ohio -[2l] Appl. No.875,242

[22] Filed Nov. 10, 1969 [45] Patented Aug. 31,197! [73] AssigneeOglebay Norton Company Cleveland, Ohio [54] APPARATUS FOR FORMING AMEMBER FROM A SLURRY 01- MATERIAL 5 Claims, Drawing Figs.

[52] U.S.Cl 1. 164/160, /27, 25/016. 19. 162/385. 162/387, 162/407,164/7, 264/87 [511 lnt.Cl 1322c 15/22 Field Search l64/7,33, 25/129,27,DIG. 16. D10. 19; 264/87; 162/382, 385, 387, 407

[56] References Cited UNITED STATES PATENTS Re. 24.860 8/1960 Kyle162/387 X 1,336,180 4/1920 Allen et al. 264/87 2.512.275 6/1950 Hawk25/83 164/33 x Primary Examiner-J. Spencer Overholser AssistantExaminer-John E. Roethel Auorney--Yount and Tarolli ABSTRACT: Animproved machine or apparatus for forming member from a slurry ofrefractory material includes a pair of mold sections which cooperate toform a cavity. A flexible diaphragm extends around the mold sections andis movable to an inwardly and downwardly sloping position to form atrough connected in fluid communication with the mold cavity. The moldcavity is flooded by filling the troughwith the slurry of refractorymaterial. Water is then drawn from the slurry in the mold cavity to forma wet-cake of refractory material. The water content of this wet-cake ofrefractory material is at least partially controlled with an adjustabletimer which regulates the length of time for which wateris drawn fromthe mold cavity. After sufficient refractory material has been depositedin the mold cavity to form a wet-cake having the shape of the member tobe formed, the diaphragm is moved to an outwardly and downwardly slopingposition to enable excess slurry to flow away from the mold sections andinto a receptacle. While the diaphragm is in this outwardly anddownwardly sloping position, a water and airspray or washdown is appliedto the area around the upper mold section to remove any refractorymaterial which may settle out of the excess slurry. The excess slurry ispumped from this receptacle to a main mixing or batch tank where it ismixed with a relatively large quantity of the slurry. Therefore, whenthis excess slurry is subsequently reused, it will have a water contentor consistency corresponding to that of the main batch of slurry.

PATENTED AUB3I IBYI sum 1 OF 7 M w R w E w r M M BY I ATTORNEYSPATENTEDAUG31 ism 3.602.287

- hemp 58o PLUG AIR L 5'4 MOLD AIR 1D m! I QOOMV-I L {$608 600 524 MOLDVACUUM L6Qo v- 1 F362 MDR-4 I m HiQSZMOR-S f l V L Q608vT-3 502 ERD-2 CZ 4 I Al FIG. I4A 1 APPARATUS FOR FORMING A MEMBER FROM A SLURRY OFMATERIAL This invention relates generally to an apparatus for forming amember by depositing material from a slurry of the material in a moldcavity and providing a flow of liquid to wash away excess particles ofthe material.

Hot tops are commonly used in connection with the casting of ingot steeland frequently include bottom rings to insulate the bottom of a metalliccasing from the molten steel. These bottom rings should all have thesame density in order to consistently provide desired strength andinsulating characteristics. In addition, the bottom rings should have apredetermined axial thickness to enable them to be readily clipped orotherwise secured to the metal casings.

Bottom rings for hot tops are advantageously formed by a moldingprocess. This molding process includes flooding a mold cavity with aslurry of refractory material. Suction is then applied to the slurry inthe mold cavity to draw off water from the slurry and deposit refractorymaterial in the mold cavity to form a wet-cake ring. This wet-cake ringhas the same configuration as the bottom ring of the hot top and issubsequently dried or cured in a suitable oven to complete the processof making the bottom ring for the hot top. An apparatus and method formaking hot top bottom rings by this process is disclosed and claimed inapplication Serial No. 875,276, filed Nov. 10, I969 by Charman et al.entitled Method and Apparatus for Forming a Member From a Slurry ofMaterial" and assigned to the same assignee as the present application.

If bottom rings produced by this molding process are to have the samedensity so as to provide similar strength and insulatingcharacteristics, the wet-cake rings must all have substantially the samewater content. However, the water content of the slurry of refractorymaterial from which the wet-cake rings are formed varies from batch tobatch. Therefore, varying amounts of water must be removed fromdifferent batches of slurry to form wet-cake rings having the same watercontent. In addition, the amount of water drawn off from the slurry willvary with the size of the wet-cake ring being formed. Since therefractory material and water forming the slurry tend to separate, theexcess slurry from the forming of one wetcake ring will have a differentwater content and consistency than the slurry conducted from a mixingtank to form the next ring. Therefore, this excess slurry and anyparticles of refractory material which may settle out should be returnedto the main batch of slurry before being reused to thereby tend tominimize variations in the water content of the slurry.

Another object of this invention is to provide a new and improvedapparatus for forming a member from a slurry of refractory materialwherein the apparatus includes first and second mold sections whichcooperate to form a mold cavity corresponding to the shape of themember, flexible diaphragm means movable between a first positionforming a trough for directing slurry toward the mold cavity to enablethe mold cavity to be flooded with slurry and to hold slurry in excessof the amount required to flood the mold cavity and a second positionenabling the excess slurry to flow away from the opening to the moldcavity, and wherein any excess particles of refractory material aroundthe mold cavity are washed away from the mold cavity while the diaphragmmeans is in the second position.

Another object of this invention is to provide a new and improvedapparatus in accordance with the next preceding object and wherein apress member is associated with the mold sections to form a portion ofthe member to a predetermined thickness, a manifold means being mountedon the press member to provide a flow of liquid which effects theaforesaid washing away of excess particles of refractory material.

These and other objects and features of the invention will become moreapparent upon a consideration of the following description taken inconnection with the accompanying drawings wherein:

FIG. I is a partially broken away elevational view of a machine orapparatus operable to form a member from a slurry of material bydepositing the material in a mold cavity;

FIG. 2 is a partially broken away elevational view, taken generallyalong the line 2-2 of FIG. 1, further illustrating the construction ofthe apparatus;

FIG. 3 is a plan view, taken generally along the line 3-3 of FIG. I,further illustrating the construction of the apparatus;

FIG. 4 is a fragmentary sectional view illustrating the relationshipbetween upper and lower sections of the mold in a closed positionforming the mold cavity;

FIG. 5 is a schematic illustration of the apparatus of FIG. 11 in anopen condition at the beginning ofa molding operation;

FIG. 6 is a schematic illustration of the mold sections in a closedposition forming a mold cavity;

FIG. 7 is a schematic illustration of the apparatus with the moldsections in a lowered position and a flexible diaphragm forming a troughfor holding slurry to flood the mold cavity and maintain a head ofslurry on the mold cavity;

FIG. 8 is a schematic illustration of the mold sections in a raisedcondition in which the flexible diaphragm slopes downwardly andoutwardly to enable excess slurry to flow away from the mold sections;

FIG. 9 is a schematic illustration of the forming of an upper surface ofthe member by moving a press ring downwardly relative to the moldsections and into engagement with an exposed surface of wet-cakematerial deposited in the mold cavity',

FIG. I0 is a schematic illustration of a mold in an open position with awet-cake member held on the upper mold section by the application ofvacuum to the member;

FIG. II is a schematic illustration of depositing of the wetcake memberonto a shuttle assembly;

FIG. 12 is a schematic illustration, similar to FIG. 5, of the apparatusin a position for initiating a second molding operation;

FIG. 13 is a schematic illustration of hydraulic and pneumatic circuitryfor effecting operation of the apparatus of FIG. I; and

FIGS. 14 and 14a are illustrations of electrical circuitry forcontrolling the operation of the apparatus.

The present invention provides an improved molding machine or apparatus20 for forming a member from a slurry of material washing excessparticles of slurry away from a mold cavity. Although the apparatus 20can be utilized for molding many different kinds of members for use inmany different types of environments, it is contemplated that theapparatus will be utilized for the molding of bottom rings for use inhot top assemblies. When bottom rings for hot tops are being formed, theslurry utilized in association with the apparatus 20 advantageouslytakes the form of a refractory slurry as set forth in U.S. PAT. No.3,468,368 to Charm-an et al. However, other slurries could be used ifdesired.

The molding apparatus 20 (FIGS. 1-3) includes a lower mold section orbox 22 and an upper mold section or plug 24 which are movable relativeto each other from an open position (FIGS. I and 2) to a closed position(FIG. 4). In the closed position the plug 24 and mold section 22cooperate to form a mold cavity 26. The mold cavity 26 has theconfiguration of a rectangular ring conforming in shape to the desiredshape for a bottom ring of a hot top.

To form a bottom ring, a slurry of refractory material is conducted froma main mixing tank 30 (FIGS. 1 and 2) to a dis tributing trough or tank34 by a conduit 36. The slurry is then conducted from the distributingtank 34 through hoses 38 to a trough 42 formed by a flexible diaphragmd4 (FIGS. 3 and d). The diaphragm as slopes inwardly and downwardly(FIG. 4) to direct slurry through an opening 46 into the mold cavity 26.In addition, the trough 42 holds excess slurry to provide a fluidpressure head on the mold cavity 26.

Suction is then applied to the mold sections 22 and 24 by conduits 48and 50 (FIG. I) which are connected to a source of low pressure orvacuum. This suction draws water and other liquid from the slurry in themold cavity 26, through foraminous walls of the mold sections 22 and 24,to thereby promote the depositing of refractory material in the moldcavity in the form of a wet-cake ring. Once the wet-cake ring has beenso formed, the diaphragm 44 is movable to an outwardly and downwardlysloping position (FIGS. 1 and 2) to enable the excess slurry held in thetrough 42 to flow or run off the diaphragm into a slurry funnel trayassembly or receptacle 54. The excess slurry is drawn from the trayassembly 54 through a conduit 56 (FIG. 2) by a pump 58 and returned tothe mixing tank 30. The resulting wet-cake ring is then removed from theapparatus 20 and dried in a suitable oven.

The operation of the molding machine or apparatus 20 is illustratedschematically in FIGS. through 12. The molding machine is shown in aninitial condition in FIG. 5 with the mold sections 22 and 24 spacedapart. The upper mold section or plug 24 is lowered by operation of amain piston and cylinder assembly 60 (see FIGS. I and 3) to move theupper mold section or plug 24 into engagement with the lower moldsection 22 to thereby define a mold cavity 26 (FIG. 4). This vertical4). of the upper mold section or plug 24 is guided by a pair of rods 64and 66 which extend through sleeves 68 and 70 on a base frame 71 of theapparatus 20 (FIG. 1). The guide rods 64 and 66 are connected to a frameassembly 72 to which the main piston and cylinder assembly 60 isconnected by an air spring or secondary piston and cylinder assembly 76.

Once the mold sections 22 and 24 have been closed, they are loweredtogether by continued operation of the main piston and cylinder assembly60 and operation of a pair of table piston and cylinder assemblies 80.The piston and cylinder assemblies 80 are operable to raise and lower atable 82 on which the lower mold section 22 is mounted. This downwardmovement of the two mold sections 22 and 24 moves the flexible diaphragm44 from the downwardly and outwardly sloping position of FIG. 6 to thedownwardly and inwardly sloping position of FIG. 7 to form the trough 42for holding the slurry 86 of refractory material. The flexible diaphragm44 is made of a polymeric material, such as synthetic rubber, and hasthe configuration of a rectangular ring. Therefore, the trough 42 formsa rectangular moat extending around the cooperating mold sections 22 and24 to enable the slurry 86 to enter the mold cavity 26 through theopening 46 which is coextensive with the bottom of the trough 42.

Once the mold cavity has been flooded with the refractory slurry 86,suction or vacuum is applied to the slurry in the mold cavity 26 throughforaminous walls 90 and 94 of the mold sections 22 and 24 (see FIGS. 1and 4). This suction draws the water from the slurry in the mold cavity26 to promote the depositing of refractory material from the slurry 86in the mold cavity. As the water is withdrawn from the slurry in themold cavity 26, excess slurry from the trough 42 enters the mold cavitythrough opening 46. Therefore after a short time, the mold cavity 26 isfilled with a wet-cake of refractory material deposited from the slurry.This deposited refractory material forms a wet-cake ring 98 (FIG. 7)havinga configuration corresponding to that of the mold cavity 26.

Once the wet-cake ring 98 has been formed in the mold cavity 26, themold sections 22 and 24 are raised by operation of the piston andcylinder assemblies 60 and 80 (see FIG. 8). Raising the lower moldsection 22 moves the diaphragm 44 to an outwardly and downwardly slopingposition so that the excess slurry 86 flows over an outer edge portion102 of the diaphragm 44 and through a space 104 between the outer edgeportion of the diaphragm and an outer wall 106 of the slurry funnel trayassembly 54 (see FIGS. l, 2 and 8). The tray assembly or receptacle 54has an inner wall 110 which is connected with the outer wall 106 by abottom wall 112. As is perhaps best seen in FIG. 2, this bottom wall 112slopes downwardly toward a receiving area I14 which is connected influid communication with the conduit 56 through which slurry is pumpedback to the mixing tank 30 where it is mixed with the relatively largebody of slurry contained therein be fore being used to form anotherring.

The consistency or water content of the excess slurry retained in thetrough 42 is different from that of the slurry when it is initiallyconducted from the mixing tank 30. This is because the refractorymaterial in the excess slurry tends to settle out from the water. Therefractory material which settles out of the excess slurry tends togravitate toward the open-- ing 46 to the mold cavity 26 and impedessubsequent filling of the mold cavity. This can result in cavitation inthe wet-cake ring 98 and variations in the water content of the slurryin the mold cavity. In accordance with the present invention, a waterand air spray or washdown is applied to the area around the plug orupper mold section 24 by a manifold ring 116 when the diaphragm 44 is inthe outwardly and downwardly sloping position of FIGS. I and 9 to removeany refractory material which may settle out of the excess slurry in thetrough 42. The excess slurry is returned to the tank 30 where it ismixed with a large body of slurry so that the slurry used for makingsuccessive wet-cake rings 98 will have substantially the same watercontent. Therefore, cavitation and variations in the water content ofthe wet-cake rings 98 tend to be minimized so that successive wet-cakerings have similar strength, density and drying characteristics.

The dried ring 98 will be utilized in a hot top assembly where the ringwill have to cooperate with other parts of the hot top assembly (see US.Pat. No. 3,468,368). Therefore, it is important that the dimensions ofthe ring 98 be formed exactly. Since the dimensions of the mold cavity26 are exactly formed by the foraminous surfaces and 94 of the moldsections 22 and 24, only the area of the wet-cake ring 98 adjacent tothe opening 46 to the mold cavity is free to vary. However, the moldingmachine 20 includes a press ring 1118 which is fixedly connected to theframe 72 (see FIGS. 1 and 2) and extends around the mold section 24. Thepress ring 118 is movable downwardly relative to the mold sections 22and 24 by operation of the piston and cylinder assembly 60 (see FIGS. 8and 9). During this downward movement of the press ring 118, the airspring or secondary piston and cylinder assembly 76 is forciblyretracted so that the press ring "8 moves axially relative to the uppermold section or plug 24 while the plug and lower mold section 22 remainstationary relative to a floor or other support surface 122 upon whichthe molding ap paratus 20 is supported. In its lowered position, thepress ring 118 extends into the opening 46 to engage the refractorymaterial deposited in the mold cavity 26 to exactly form the uppersurface of the wet-cake ring 98.

The fully formed wet-cake ring 98 is then withdrawn from the mold cavity26 and dried in a suitable oven. To withdraw the wet-cake ring 98 fromthe mold cavity 26 air pressure is applied through the conduit [26 (FIG.10) to the lower mold section 22 when the mold sections are in theclosed position of FIG. 9. This air pressure is applied against thelower surface of the wet-cake ring 98 through the foraminous surfaces 90of the lower mold section 22 and enables the wetcake ring to be readilyseparated from the lower mold section. The suction or vacuum ismaintained on the upper mold section 24 through. the conduit 48. Thus,the wet-cake ring 98 is urged or sucked upwardly against the plug 24 andmoves upwardly therewith as the plug is raised from the closed positionof FIG. 9 to the open position of FIG. 10 by operation of the piston andcylinder assembly 60.

A shuttle tray is then moved between the mold sections 22 and 24 toreceive the wet-cake ring 98 from the plug 24. To facilitate depositingof the wet-cake ring on the shuttle tray I30, air pressure is applied tothe plug 24 through a conduit 132 (FIG. 11). This air pressure isapplied against the upper surfaces of the wet-cake ring 98 through theforaminous surfaces 94 of the plug 24. Therefore, the wet-cake ring 98drops downwardly onto the shuttle tray 130 in the manner illustratedschematically in FIG. 11. The shutt e tray 1-30 is then withdrawn frombetween the mold sections 22 and 24 (FIG. 12). The wet-cake ring 98 issubsequently transported to an oven where it is dried or cured in aknown manner. The density of successive bottom rings produced by themolding machine 20 is substantially the same since the moisture contentof the wet-cake rings 98 is substantially constant.

When the plug 24 is moved from the open position of FIG. 5 to the closedposition of FIG. 6, the plug tends to move slightly sidewardly relativeto the lower mold section 22 to enable the plug 24 to become alignedwith the mold section 22. To promote this alignment, a plurality ofpositioning pins 140 project upwardly from the lower mold section 22(FIG. I) and engage suitable holes 142 formed in the plug 24 to alignthe plug 24 and lower mold section 22. The provision of the air spring76 enables the plug 24 to move sidewardly somewhat relative to the frame72 to which the press ring 118 is fixedly connected to enable the moldsections 22 and 24 to become properly aligned. The press ring 118 ismovable axially relative to the plug 24 between the position shown inFIGS. 8 and 9. Accordingly. the guide rods 6d and 66 extend through thebase frame 71 and are fixedly secured at 146 and 148 to a crosspiece 150of the frame 72. The plug 2d is fixedly connected by guide rods 154 and156 with the crosspiece 158 which is connected to a piston rod 162 ofthe air spring 76. The air spring 76 is pivotally connected at I72 tothe piston and cylinder assembly 60 which is fixedly secured to theframe 72 and press ring 118. A universal or ball-type connection 173 isprovided between the plug 24 and piston rod 162 of the air spring 76.Therefore, relative movement can occur between the plug 24 and the frame72 at the joints I72 and 173. In addition, the plug 24 can be movedrelative to the frame 72 by moving the piston rod 162 to retract the airspring 76. Retraction of the air spring 76 enables the press ring I18 tomove between the raised and lowered positions of FIGS. 8 and 9.

It is contemplated that different size members or hot top rings will bemolded with the apparatus 20. Therefore, the plug 24 and lower moldsection 22 can be readily replaced with other mold sections to formeither larger or smaller mold cavities. To facilitate replacement of theplug 24, the guide rods 154 and 156 are removable fastened at 180 and182 (see FIGS. 1 and 4) to the crosspiece 158. Similarly, a crosspiece186 of the frame 72 is detachably fastened at 1% and 1192 withprojections from the support member 150. Thus, by loosening theconnections 180, 182 the plug 24 can be exchanged for another plug. Ifthis other plug has a different outside dimension, the press ring 118can be removed from the frame 72 by merely loosening the connections 190and 192 so that a press ring of the proper size can be connected to thesupport member 150.

Similarly, the lower mold section 22 can be disconnected from the table82 by quick-release connections 200 which secure the mold section 22 tothe table. A mold section of the desired size can then be mounted on thetable 82. Of course, it may be necessary to replace the diaphragm 44with a diaphragm of a different size if the outside dimensions of thelower mold section 22 vary.

The diaphragm 44 is mounted on the slurry funnel tray assembly 54 bymeans of rods 206 around which the outer end portion 102 of thediaphragm 44 extends. (See FIG. 1). These rods 206 have outwardlyprojecting end portions 208 which engage brackets 210 at the corners ofthe slurry funnel tray assembly 54 (see FIG. 3). An inner end portion214 of the diaphragm 44 is releasably clamped to the lower mold section22. Thus, the diaphragm can be readily removed for replacement purposesby merely disengaging the rod ends 208 from the brackets 210 anddisengaging the diaphragm from the lower mold section 22.

The mold cavity 26 has an innermost end portion 216 (FIG. 4) into whichthe slurry must be drawn and refractory material deposited if thewet-cake ring 98 is to have the desired configuration. Therefore, theforaminous surface 90 of the lower mold section 22 has an axiallyextending end wall 218 (FIG. 4%) through which suction is applied to theslurry in the mold cavity. In addition, the foraminous surface 94 of theplug 24 extends across the transverse extent of the end portion 236 toenable suction to be applied to the slurry in the end portion 216 fromthe plug 24. These foraminous surfaces 218 and 96 result in suctionbeing applied to the slurry in the mold cavity 26 in such a manner thatslurry is drawn into the end portion 216. Therefore, refractory materialis deposited in the end portion 216 and the innermost portion of thewet-cake ring 98 can be readily formed without defects resulting frominadequate deposits of refractory material.

Hydraulic control circuitry 250 for moving the plug 24 and mold 22between the positions illustrated in FIGS. 5 through FIG. 12 is shownschematically in FIG. 13. Pneumatic control circuitry 252 forcontrolling the application of high pressure air and suction to the moldcavity 26 is also illustrated in FIG. 13. Electrical control circuitry254 for controlling the operation of the hydraulic circuitry 250 andpneumatic circuitry 252 is set forth schematically in FIGS. 14 and Me.It should be noted that the control circuitry of FIGS. 13 and I4 hasbeen shown in a simplified form to avoid prolixity of description.Specifically, well known features such as interlocks, manual overrides,pressure and flow regulators, etc., have been omitted from thecontrolcircuitry of FIGS. 13 and 14.

The electrical control circuitry 254 includes six main subcircuitsincluding a subcircuit 25$ for controlling the operation of thehydraulic circuitry 2% to move the plug 2 5 and mold 22 from the openposition shown in FIG. 7. Once the plug 24 and mold 22 have beenlowered, a slurry feed control subcircuit 260 is operable to enableslurry to flow into the trough 62 formed by the diaphragm 44 (FIG. 7).Subcircuit 262 is operable thereafter to raise the mold section 22 whilemaintaining the plug 24 in the closed position (see FIG. 8) so that theexcess slurry flows off the diaphragm 44 into the slurry funnel trayassembly or receptacle 54. Following a con trolled dewatering or suctiontime period which varies with different ring sizes and slurryconsistencies, the press ring 118 is then moved to the lowered positionunder the control of subcircuit 264 which, after a predetermined timeperiod, is operable to effect a raising of the press ring and plug 2d tomove the mold sections to the open position of FIG. 10. A shuttlecontrol subcircuit 266 is then operable to effect movement of theshuttle tray to a position intermediate the mold sections 22 and 24 andto withdraw the shuttle tray 130 with the wet-cake ring 28 disposedthereon. Finally, subcircuit 270 is operable during the operation ofsubcircuits 258 through 266 to actuate the pneumatic control circuitry252 and thereby control the application of high pressure air and suctionto the mold cavity.

Assuming that the plug 24 and mold 22 are in the open position of FIG.5, operation of the molding machine or apparatus 20 is initiated bymanually pressing a start button 274 (FIG. 14). Pressing the startbutton 274 initiates movement of the plug 2 from the raised position ofFIG. 5 toward the lowered position of FIG. 6 by completing a circuitbetween power lines 276 and 270 through a lead 280 to energize the SPDrelay 284. Energization of the SPD relay 28d closes contacts ZfMSPD-I tohold the relay energized. In addition, ZMSPD-Z contacts are closed toeffect energization of a plug-down solenoid 2%. Energizing the plug-downsolenoid 286 operates the control valve 2% (FIG. 13) from its normal orneutral position in which a flow of hydraulic fluid from a reservoir 296through conduit 296 under the influence of a pump 2% is blocked. Whenthe plug-down solenoid 286 is energized, valve body 300 of the valve 290is moved toward the right, as viewed in FIG. 13, to connect the upperend portion of a cylinder 30d of the main piston and cylinder assembly60 in communication with the pump 2% through conduit 306 and the conduit296. The lower end portion of the piston and cylinder assembly 60 isexhausted to a reservoir 308 through the valve body 300 and a conduit310. Thus, high pressure fluid on the upper surface of piston 3M movesthe plug 24 downwardly toward the mold 22.

As the plug 24 is lowered, it moves into engagement with the lower moldsection 22. At that time a normally open TD limit switch 312 (FIG. M) ina limit switch assembly 320 (see FIG. 2) is closed to initiate downwardmovement of the table 82 and mold section 22. It should be noted thatthe limit switch assembly 320 includes a plurality of spaced switcheswhich are mounted in a fixed relationship with the frame 71 of themolding apparatus 20 and a connector rod 322 which is pivotallyconnected to the frame 72. Therefore, vertical movement of the plugmoves the connector rod 322 relative to the switches of the limit switchassembly 320 to actuate these switches in response to the frame 72 beingmoved to any one of a plurality of positions under the influence of themain piston and cylinder assembly on. The limit switches in the assembly320 have one-way actuators so that they are operated only in response tomovement of the Connector rod 322 in one direction. either up or downdepending upon the cond tion to which the limit switch is to beresponsive.

Closing the normally open TD limit switch 3R8 energizes the STD relay322 through normally open contacts ZtldSPD-S of the now energized SlPDrelay 2%. The STD relay 322 is maintained energized by closing ofnormally open 322STD-l contacts. Closing of normally open 322STD-2contacts completes the circuit to energize the table-down solenoid 32d.Encrgization of the solenoid 324 operates the table control valve 328(FIG. 13) by moving a valve body 33-0 toward the left, as viewed in H6.13, to connect the upper ends of cylinders 332 and 3343 with highpressure fluid from the pump 293 through a passage 336 in the valve body330 and fluid conduits 296, 33%, 340, and 3&2. This high-pressure fluidcauses pistons 346 and 3 88 to move downwardly and exhaust fluid fromthe cylinders 332 and 334 through conduit 352 and valve body passage 354to a reservoir 35s.

The plug 24 and mold 22 move downwardly together from the position shownin FIG. 6 to the position shown in FlG. 7. When the plug and mold 24 and22 reach the lowered or down position of FIG. 7, a normally opened MDlimit switch 360 in the limit switch assembly 320 is closed to energizeMDR relay 362. Energization of the MDR relay 362 opens normally closedcontacts 362MDlR-l and IitSZMDJRZ to release the holding circuits forthe 32,2STD and Zfi iSPD relays. The deenergization of these relaysopens contacts 322?;STD-2 and 284SPD-2 to deenergize the table-downsolenoid 324 and plug-down solenoid 2.36. The control valves 32% and 294then return to the normal positions illustrated in FlG. l3 and blockfluid flow from the cylinders 332, 334, and 3&4 to thereby maintain theplug 24 and mold 22 in the position illustrated in FIG. 7.

Once the plug 24 and the mold 22 have been lowered to the position shownin H0. 7, valve 3'70 of the slurry feed line as is opened by an actuatorassembly 372 (FlG. l) to feed slurry from the main tank 34 to thedistributing tank 34. The slurry flows from the distributing tank 34through the hoses 38 to the trough 42 formed by the diaphragm 414 aroundthe plug and mold 22. The slurry feed control subcircuit 260 (HO. M)includes timers which regulate the length of time for which the valve370 is opened to thereby control the quantity of slurry which flows intothe trough &2. Vacuum is then applied to the slurry in the mold chamber26 to draw off water from the slurry contained therein and promote thedeposit of refractory material in a wet-cake in the mold chamber. Asupplementary or secondary charge of slurry is provided to maintain thehead of slurry in the trough d2 substantially constant even throughslurry flows from the trough into the mold cavity to makeup for thewater which is drawn off. However, it is contemplated that under certainoperating conditions the secondary charge of slurry may be omitted.

When the plug 24 and mold 22 reach the lowered position of FIG. 7 andthe MD limit switch 360 is closed to energize the MDR relay 362, acharge timer 374CT is energized by a closing of normally open lllMDh-lcontacts. in addition, a slurry feed solenoid 376 is energized by theclosing of normally open 36ZMDlR-2 contacts to operate the valve 370 tothe open condition so that slurry flows through the conduit as into thedistributing trough 34! and from there into the trough 42 formed by thediaphragm At the end of a predetermined time period the charge timer 374operates or times out to deenergize the slurry feed solenoid 37s andeffect a closing of the valve 370. it should be noted that the chargetimer 374 is adjustable to enable the period of time for which the valve376 is opened to be varied to thereby vary the quantity of slurry whichis fed into the trough 42. Operation or timing out of the charge timer37 i dcenergizes the slurry feed solenoid are by closing normally opencontacts J'T tlCT-ll to thereby energize CTR relay 11bit through thenormally open 362MDR-2 contacts ofthe now energized MDR relay 3 62.Energization of the CTR relay 3841 opens normally closed 380 CTR-lcontacts to deenergizc the charge timer 37s and opens normally closedJiiltlCTFbZ contacts to decnergize the slurry feed solenoid .3761. TheCTR relay 380 is then maintained energized over its own normally opencontacts BlitlCTR-J.

A predetermined time period after the initial charge of slurry flowsinto the trough 42, the slurry feed valve 370 is again opened to enablea secondary or supplemental charge of slurry to flow into the trough 32.Thus, operation of the CTR relay 380 to energize DT timer $45 which isadjustable to enable the secondary or supplemental charge to be delayedfor a desired time period after the initial or primary charge oislurryis provided in the trough 32. At the end of the selected time period,the DT timer 35% operates or times out to close contacts 384DT-ll toeffect energization of DTR relay see which is then held energized overits own normally open contacts JlbEiDTR-l. Encrgization of the DTR relaysen opens normally closed scams-2 contacts in the holding circuit forthe CTR relay Bill). The resulting deenergization of the CTR relay 38denables normally closed contacts ESBOCRT-E to again close to completethe circuit for energizing a slurry feed valve through the EMSEMDlR-Zcontacts of the now energized MDR relay. Normally closed SlldDTR-Bcontacts in the circuit for energizing the CT timer 3'74 are opened toprevent reactivation of this timer,

A secondary charge timer 3%] controls the duration of time for which theslurry feed valve 3% is opened to enable the secondary charge to flowinto the trough $2. The secondary charge timer 3941 is selectivelyadjustable to enable the time period for which the slurry feed valve 376is opened to be varied to thereby enable the size of the secondarycharge of slurry to be adjusted. Thus, energization of the DTR relay 38bto initiate flow of the secondary charge closes normally open contacts386DTR-4 to energize the SCT timer 398. At the end of the predeterminedtime period when the SCT timer 390 operates or times out, normally opentimer contacts 3%1SCT l are closed to energize the SCTR relay 392 whichis then held operated over its own contacts 392SCTl1-ll. Operation ofthe SCTlFl relay 392 opens normally closed contacts 392SCTR-2 todcenergizc the SCT timer 39hv Normally closed contacts 392S-C'lR-3 areopened to open the holding circuit for the DTR relay 386. In addition,normally closed contacts BQIZSCTR-d are opened to deencrgize the slurryfeed valve solenoid 37s. Thus, operation of the timer 390 effectsdeenergization of the slurry feed valve solenoid 376 to stop thesupplemental charge of slurry to the trough d2.

After the initial and supplemental charges of slurry have been providedin the trough 82, the plug 24 and mold 22 are moved upwardly to theposition illustrated in FIG. 8 in which the table $32 is fully raised.To effect this movement, the subcircuit 262 effects actuation of thevalves 290 and 32$ (see H6. 13) to operate the piston and cylinderassemblies 6! and 80. Accordingly, operation of the SCTR relay 392., atthe end of the supplemental charge, closes normally open contacts392SCTR-5 to complete a circuit for energizing the MU relay 3%,Energization of the MU relay 396 closes normally open contacts BWiMU-llto energize STU relay 398. Energization of the STU relay 398 closesnormally open contacts 398STU-ll to energize the table-up solenoid 500.In addition, encrgization of the STU relay 398 closes contacts 393STU-2to provide a locking circuit for the relay. The MU39tS relay isdeenergized by opening of normally closed EWBSTU'B contacts to therebyeffect dccncrgization of the SCT}! relay 392; by opening B ilbMU-Zcontacts in the holding circuit for the SCTR relay 392. Energization ofthe STU relay 3% also closes normally open contacts EQSSTU-d to energizethe plug-up solenoid 46% along with the tablc-up solenoid M39 to therebyeffect upward movement of both the plug 24- and lower mold section 122,.

The foregoing energization of the plug-up solenoid 404 effects operationof the valve 290 toward the left as viewed in FIG. 13 to conduct highpressure fluid through a passage 406 in the valve body 300 to theconduit 310 to thereby move the piston 314 upwardly to raise the plug24. Energization of the table-up solenoid 400 efi'ects operation of thevalve 328 toward the right, as viewed in FIG. 13, to connect highpressure fluid through the conduit 352 to the lower side of thecylinders 332 and 334 and to exhaust the upward side of these cylindersthrough the conduit 340 to thereby effect upward movement ofthe table82. This upward movement of the table 82 continues until the moldsections 22 and 24 reach the position shown in FIG. 8 and normallyclosedlimit switches TU-l and TU-.2 (FIG. 14) of the limit switch assembly 320are opened. Opening these limit switches deenergizes the STU relay 398so that the table-up solenoid 400 and plug-up solenoid 404 aredeenergized by opening of the 398STU-l and 398STU-4 contacts.Deenergizing the table-up solenoid 400 and plug-up solenoid 404 enablesthe valves 290 and 328 of FIG. 13 to return to their normal positions,under the influence of suitable biasing springs, to block fluid flow toand from the piston and cylinder assemblies 60 and 80. Therefore, themold 22 and plug 24 are maintained in the position shown in FIG. 8 bythe piston and cylinder assemblies-60. and 80.

After the plug 24 and lower mold section 22 have remained in theposition shown in FIG. 8 for a predetermined time period during whichvacuum is applied to the mold cavity 26,

the press ring 11 8 is lowered by operation of the mainpiston andcylinder assembly'60 while the piston and cylinderassemblies 80 retainthe table in the raised position. It should be noted that this downwardmovement of the pressring 118 is against the influence of the air spring76 (FIG. 13) which'is continuously connected to a source ofair pressurethrough conduits 408, 410 and 412. The force exerted by the main pistonand cylinder assembly 60 is able to overcome the influence of the airspring 76 so that thepiston rod 162.forces thepiston 416 upwardly, toenable the press ring 1 18 to move downwardly relative to the plug 24fromtheposition shown in FIG. 8 to the position shown in FIG. 9.-

Accordingly, immediately after the plug 24 andmold 22. are raised to theposition shown in FIG. 8, PRDR relay 420'is energized by a closing ofnormally open limit switch contacts TU-3 (FIG. 14a) in the limit switchassembly 320. The PRDR relay 420 isthen energized through the normallyopen contacts 398STU-5 of the STU relay 398 (FIG. 14) which is releasedimmediately after the plug 24 and mold 22 have reached the raisedposition of FIG. 8. The PRDRrelay 420 is maintained energized throughholding contacts 420PDR-l to energize PRDT timer 424 over normally opencontacts 420PRDR-2' of the energized PRDR relay 420. The PRDT timer 424delays movement of the press ring 118 from the raisedposition of FIG. 8to the lowered position of'FlG. 9 for a predetermined time period afterthe plug 24 and mold 22 reach the position of FIG. 8 and during whichvacuum is applied to the mold cavity 26. The timer424 is selectivelyadjustable to enable this time period to be varied to accommodatevariations in the length of time for which vacuum is applied to the moldcavity.

At the end of the selected time period, the PRDT timer 424 operates ortimes out to close normally open contacts 424PRDT-1 to thereby energizePR relay 426whichis then held energized over its own contacts 426PR-1.In addition, operation of the PRDT timer 424 effects deenergization ofthe PRDR relay by opening the normally closed contacts,

424PRDT-2 in the holding circuit for the PRDR relay 420; Uponenergization of the PR relay 426, contacts .426PR-2 .in the subcircuit258 are closed to energize the plug-down solenoid 286 and therebyactuate the control valve 290 toward the.

right as viewed in FIG. 13 to operate the main piston and cylinderassembly 60 and lower the press ring 118 relative to the plug 24 whichis retained against downward movementby engagement with the mold 22.

When the press ring 118 reaches the down or lowered position of FIG. 9,a one-way normally closed PRD-l' liinit switch 430, in the limit switchassembly 320, is opened to deenergize the plug-down solenoid 286 so thatthe valve 290 returns to its normal position in which the flow of fluidto and from the piston and cylinder assembly 60 is blocked by thelyalvebody 300. Simultaneously with the operation of the PRD-l limit switch, anormally open PRD-2 limit switch (FIG. 14a) is closed to energize aselectively adjustable PRT timer 434. The PRT timer 434 controls thelength of time for which the press ring 118 is in the lowered position.Upon operation or timing out of the PRT timer 434, normally opencontacts 434 PRT-1 close to complete a circuit for energizing PRU relay440 which initiates upward movement of the press ring 118 by closingnormally open contacts 440PRU-2 in the subcircuit 262 (FIG. 14) tothereby energize the plug-up solenoid 404. i

The PRU relay 440 is held up by its own normally open contacts 440PRO-3.Of course, energization of the plug-up solenoid 404 actuates the valve290 to the left as viewed inFIG.

13 to retract the piston and cylinder assembly 60 and thereby raise thepress ring 118. It should be noted that operation of the PRT timer 434also'opens norm ally*closed contacts 434PRT-2 in the holding circuit forthe PR relay 426.

The PRU relay 440 and plug-up solenoid 404 are maintained energizeduntil the plug 24'reaches its uppermost position (FIG. 10). The normallyclosed PU-I limit switch (FIG.

14a) in the limit switch assembly 320 is then operated to open theholding circuit for the PRU relay 440. Therefore, normally open contacts440 PRU-2 are released to deenergize the plugup solenoid 404 with theplug 24 and mold 22 in the open position ofFIG. l0. 7

The shuttle tray 130 is then moved to a position between the plug 24 andmold .22. The wet-cake ring 98 is deposited on the shuttle tray 130which is then withdrawn to enable the wetcake ring to be transported toa drying furnace in which it is heated. Accordingly when the plug 24reaches the upper or raised position of FIG. 10, the normally openPll-2limit switch (FIG. I4ain the limit switch assembly 320 is closedtoenergize the PUR relay 446. Energization of the PUR relay 24 and mold22. In addition,

446 closes normally open contacts 446PUR-1 in the-shuttle controlsubcircuit 266 toenergize SOR relay 448-which is then-held up throughits own normally open contacts 448SOR- 1'. A shuttle-out solenoid 450 isenergized by closing normally opened contacts 448SOR-2 to effect outwardmovement of the shuttle tray to a position intermediate the raised plugnormally closed contacts 448SOR-3 are opened to deenergize the PUR relay446.

When the shuttle tray 130 reaches its outward position (FIG. 10), ,anormally closed shuttle limit switch SO-l is opened to deenergize theSOR relay 448 and the shuttle-out solenoid 450. In addition, when theshuttle tray 130 reachesits outward position, a normally open limitswitch SO-2 is closed. After operation of the PAT relay 620 in the airand vacuum control subcircuit 670, the SlRrelay 454 is energized andheld up by a locking circuit including normally open contacts 454SIR-l.Inaddition, normally open contacts 454SIR-2 will .be closed to energizea shuttle-in solenoid 458 to retract the shuttle tr-ay 130 with thewet-cake ring 98 thereon. When the shuttle assembly has reached ashuttle-in or retracted position, SH and SI-2 limit switches will beopened to deenergize the SIR re'lay 454'and the shuttle-in solenoid 458.

The foregoing movement of the shuttle tray 130 is effected by a shuttlecylinder assembly 460 (see FIG. 13). Upon energization of movedshuttle-out solenoid 450, a shuttle control valve 462 is move toward theleft, a viewed in FIG. 13, to conduct high-pressure fluid for the pump298 through a passage 464 in valve body 466 to move a piston 468 to anextended position or toward the left, as viewed in FIG. 13. A passage470 in the valve body connects the opposite end of the piston andcylinder assembly 460 with a reservoir 472. This movement of .the piston468 moves the shuttle t'ray 130 to the extended position of FIG. 10.Similarly, when the shuttle-in soleflnid from the pump 298 through apassage 474 to move the piston 468 toward the right and retract theshuttle tray 130.

7 During the foregoing operation of the apparatus 20, the electricalcontrol subcircuit 270 of FIG.l 4a is operable to actuate valves in thepneumatic circuitry 252 of FIG. 13 to apply either suction or vacuum tothe plug 24 and mold 22. .Thus,

energization of a plug-air solenoid 580 operates a valve 582 in thepneumatic circuitry 252m connect the plug 24 with a source of airthrough conduits 132, 586 and 412. Energization of a plug vacuumsolenoid590 operates a control valve 592 to 3,602,237 v. r a

I. v of the normal position of FIG. 13 t o conduct high-pressure- Theforegoing'applicationpf suction tothe mold cavity 26 has drawn waterfrom the slurry into the plug 24. Ifv the plug 24 gize the plug-airsolenoid 580 by closing of relay contacts operate a piston and cylinderassembly 594- which in turn operates ,a butterfly valve 596 to connectvacuum to the plug m cavity 26 from the-plug 24. Since the VT, timer 608deenergizes shortly after being operated, this blast of air isrelatively 24 through conduits 48, 502 and It should be noted that thevalve 592 controls the operation of the butterfly valve. 596

by connecting high-pressure air to one of the twosides of the piston andcylinder assemblies through conduits 508, 510, 410

Similarly, when a mold-air. solenoid 514 is energized, a valve 516 isoperated to connect airto'the mold 22 through conduits 1'26, 520 and412. Upon energization of a mold-vacuum sole noid524, a valve 526 isoperatedby a butterfly valve 528 with a piston and cylinder assembly 530to connect vacuum through conduits 504, 532 and 50'to mold 22. The valve526 controls the operation of the piston cylinder assembly 530 with highpressure air conducted throughtheconduits 538,

540,410 and 412. t I

and mold 22 have been moved to the lowered position of FIG. 7 and-thetrough 42 is being filled with'slurry, vacuum is applied to the moldcavity 26 through the foraminous surfaces 90 and 94 of both the plug 24and 1 mold ,22 (see FIG. 4). Thus, when. the moldand plug reach thelowered position of FIG. .7, the 360MB limit switch in thesubcircuit 258is closed to energize the MDR relay 362. Energiza- When the plug 24 tionof the MDR relay 8,62. closes normally opencontacts' 362MDR-4 and362MDR-5. in'the airand vacuum control 'subcircuit' 270 toenergize MVrelay 600 and PV. relay 60 2.-

Energizingthese I relays Icloses normally open contacts 600MV 1 and602PV-l to energize the plug-vacuum solenoid 590. and. mold-vacuumsolenoid I 524. Locking contacts 600MV-2- and '602PV-2 are also-closed.Whereafter,'the valves 592 and 526 (FIG. 13) are actuated to operate thepiston and cylinder assemblies594 and 530 and the butterfly valves i596and 528 to connect vacuum to the plug 24,and'

mold In addition, energization of the MDR relay 362 closes contacts362MDR-6 in the air and vacuum controlrcircu'itry 270 to energizeselectively adjustable VT timer 608 which controls the length of timefor which the suction is applied to the plug 24' and mold 22.

It-is contemplated that the water content of the slurry 86 will'varyfrom batch to batch. Therefore, it is necessary for vacuum or suction'tobe. applied to the slurry in the mold cavity 26 for varying lengths oftime. Accordingly, the VT timer 608 is adjustable to enable the lengthof time'which vacuum is applied to the mold cavity 26 to be varied. IHowever, the mold sections 22 and 24'will be raised to the positionshown in FIG. 7 before the selected time period elapses.;Therefore, the360MB limit switch will have opened and the MOR relay 363 will havereleased. Thus, normally open 362MDR-4, 362MDR-5 and 362MDR-6 contactswill be released before the end of the time period for which vacuum isapplied'to the mold cavity 26. During this time period after the MDRrelay 363 is released, the VT timer 608 is energized over contacts600MV-3 of thenow energized MV relay 600. When a 'the selected timeperiod for the application of vacuum has elapsed and the timer 608operated, contacts 608VT-l are 6l4PA-l. This enablesa surge or blast ofair to. flow into the short since the time delay contacts 608VT-4 soon'return to their normally open condition. Energization of the 'VTR relay610 also closes normally open contacts 6l0VTR-3 to energize MA relay 616,Energization of theMA relay 616 closes nor mally opencontacts 6l6MA-lto energize the moid-air solenoid 514. to apply air to the mold section22. This air frees the wet-cake ring 98- from the surface of the moldsection 22; I

When the PUR' relay 446 is energized by movement of the plug 24 to theraised'position, 446PUR -3 contacts are opened to release the holdingcircuit for the VTRrelay 610. v

Shortly after the application of air to the mold section 22, the PRUrelay 440 (see the press'ring control circuit 264) is energized to raisethe plug 24 upwardly to the position shown in l0. Ene'rgization of thePRU relay 440 closes 440PRU- '4 contacts in the control circuitry 270.to energize PVU relay 620 which is locked up oyer'PVU620-l contacts. Inaddition, normally open FVU620=2 contacts are closed to energize the'PV, relay 602 and plugvacuum solenoid.590 to apply vacuum to the plug24. This vacuum draws the wet-cake ring 98 against the plug 24 s'o, thatthe ring is moved upwardly with the plug in themannerjllustr'atedschematically in FIG. 10. Normally closed contacts448SOR-4 maintain the locking circuit for the PVU relay 620 intact untilthe-shuttle tray 130 reaches the extended orouter position between-themold 22 and plug 24 FIG. 10). The SQ-4 limit switch is then closed toenergize the PA relay 614 and close contacts 6l4PA-l to energize theplug-air solenoid 580. In addition, normally open'contacts 6l4PA'-2 are.closed to, enable the PAT timer 626 to be energized through the nowclosed 804 limitswitch. At the end of a preselected time period duringwhich the wet cake ring98'is deposited on the shuttle tray 130; thePATtime 626 opens normally closed contacts'626PAT-l to break the holdingcirc'uitfor the PA relay 614 to thereby ldeenergize the. plug-airsolenoid 580. In addition, normally open 626PAT-3contacts in theshuttlecontrol subcircuit 266 are closed to energize the SIR relay 454 throughthe now closed SO-2 limit switch. SIR re'lay 454 is then held energizedthrough its own normally open contacts 454SIR'-l until the shuttle isretracted or moved in and the 81-1 limit switch is opened. Aswas'previously explained, theshuttle-in solenoid 458 is energized uponenergization of the SIR relay 454.

Thepresent'invention contemplates that when the press ring 118 islowered'(see FIG. 9) slurrywhichadhered to the by a mixtureof air andwater which is conducted to a manifold outersurfaces of the plug'24 andmold 22 will be washed away ring "6 on the press ring-118 (see FIG. 1).The flow of water to the manifold ring 116 is controlledby a valve 704in the pneumatic circuit 252 (FIG. 13 Thev flow of air to the manifoldring 116 is controlled by valve 706 in the pneumatic circuit 252. Thevalve 704 is operated to an open condition by closed for a short periodof time to energize the VTR relay 610 which'is then held energized overlocking contacts 610VTRJ. Energization of the VT timer 608 openscontacts608VT-2 to open the holding circuit for the MV relay 600.

Deenergization of the MV relay 600 deenergizes the moldvacuum solenoid524. In addition, operation of the VT timer and the plug-vacuum solenoid590. 5

a.,water solenoid 708 (see FIG. 14a) and the valve 706 is operated to anopen condition by an air solenoid 710. The

solenoids 708and 710 are operated when a press ring dow'nlimitswitchPRD-2 is closed by movement of the press ring 118 from theraised position of FIG. 8 to the lowered position of FIG. 9. Normallyclosed contacts 284SPD-4are provided in the circuit forenergizing thesolenoids 708 and 710 to prevent the solenoids from being energized whenthe plug 24 is being initially lowered from the raised position of FIG.5 to the lowered position of FIG. 7. By experimentation, it has beendetermined that the air and water spray from the manifold ringamount ofwater drawn from the slurry whilethe slurry is being deposited in themold cavity 26. Thus, the vacuum timer 608 is adjustable to vary thelength of time for which vacuum or suction is applied to the mold cavity26. If a relatively wet slurry is being used, the length of time whichthe timer 608 is set for will be relatively long. However, if arelatively dry slurry is being used, the timer will be set for asomewhat shorter period. To further promote the formation of wet-cakerings 98 of a constant density, the excess slurry is collected in thereceptacle or tray assembly 54 and any particles or refractory materialwhich may settle out are returned by the pump 58 to the mixing tank 30before being reused to make a wet-cake ring. This insures that theslurry utilized for making the rings will be of substantially the sameconsistency.

Having described a specific preferred embodiment of the invention, thefollowing is claimed:

1. Apparatus for forming a member from a slurry of refractory materialsaid apparatus comprising a first mold section, a second mold sectioncooperable with said first mold section to form a mold cavitycorresponding to the shape of the member and to provide an openingthrough which slurry can enter the mold cavity, flexible diaphragm meansmovable between a first position and a second position, said diaphragmmeans in the firs position at least partially forming a trough fordirecting slurry through the openinginto the mold cavity to therebyfioodthe mold cavity and for holding slurry in excess of the amountrequired to flood the mold cavity to-thereby provide a head of slurry tocompensate for any decrease in the volume of slurry in the mold cavity,said diaphragm means in the second position enabling excess slurry toflow away from the opening to mold cavity, and means for providing aflow of liquid under pressure to wash any particles of refractorymaterial which may remain in an area around the opening to the moldcavity away from the opening when said diaphragm means is in the secondposition. I

2. Apparatus as set forth in claim 1 further including a press memberoperatively connected to said second mold section and movable relativeto said second mold section between a first position spaced apart fromthe member being formed in the mold cavity and a second positionengaging the member being formed in the mold cavity and spaced atpredetermined distance from a mold surface on said first mold section tothereby form a portion of said member in the mold cavity with athickness corresponding to the predetermined distance.

3. Apparatus as set forth in claim 2 further including control means forcontrolling the operation of said means for providing a flow of liquidunder pressure, said control means including means for initiating theflow of liquid under pressure when said press member is in its secondposition and for interrupting theflow of liquid under pressure beforesaid press member is moved to its first position.

4. Apparatus as set forth in claim 2 wherein said means for providing aflow of liquid under pressure includes manifold means mounted onsaid-press member for directing a flow of liquid under pressure towardthe area around the opening to the mold cavity, and conduit means forconducting liquid under pressure to said manifold means.

5. Apparatus as set forth in claim 4 further including means forsupplying air under pressure to said manifold means to thereby providean air and liquid mixture for washing away any particles of refractorymaterial which may remain in the area around the mold cavity.

Disclaimer 3,602,287.-Ma1"tin Eversdyk, Bedford Heights, Ohio. APPARATUSFOR FORMING A MEMBER FROM A SLURRY OF MATERIAL. Patent dated Aug. 31,1971. Disclaimer filed Mar. 23, 1972, by the assignee, Oglebay NortonCompany. Hereby enters this disclaimer to claims 1 through 5 of saidpatent.

[Oficz'al Gazette, June 6, 1972.]

2. Apparatus as set forth in claim 1 further including a press memberoperatively connected to said second mold section and movable relativeto said second mold section between a first position spaced apart fromthe member being formed in the mold cavity and a second positionengaging the member being formed in the mold cavity and spaced apredetermined distance from a mold surface on said first mold section tothereby form a portion of said member in the mold cavity with athickness corresponding to the predetermined distance.
 3. Apparatus asset forth in claim 2 further including control means for controlling theoperation of said means for providing a flow of liquid under pressure,said control means including means for initiating the flow of liquidunder pressure when said press member is in its second position and forinterrupting the flow of liquid under pressure before said press memberis moved to its first position.
 4. Apparatus as set forth in claim 2wherein said means for providing a flow of liquid under pressureincludes manifold means mounted on said press member for directing aflow of liquid under pressure toward the area around the opening to themold cavity, and conduit means for conducting liquid under pressure tosaid manifold means.
 5. Apparatus as set forth in claim 4 furtherincluding means for supplying air under pressure to said manifold meansto thereby provide an air and liquid mixture for washing away anyparticles of refractory material which may remain in the area around themold cavity.